Some reciprocating piston compressors, as for refrigeration systems, have suction and discharge valves which are resilient metal leaves or flappers that are edge mounted in cantilever fashion. Typically, a valve plate is secured to the compressor cylinder block and has suction and discharge ports for the cylinder. The suction valve is located on the underside of the valve plate, between the valve plate and the cylinder. The discharge valve is secured to the outer surface of the valve plate.
The pressure on the mounting portion of such resilient leaf valves is an important factor in the manufacture and operation of the compressor. The pressure must be sufficient to provide a reliable seal, but not so great that the thin metal of the leaf is distorted which would prevent it from seating against the flat surface of the valve plate. Prior constructions have either required several expensive parts to secure the valve to the plate and effect proper alignment of the plate with the cylinder block or have secured both of the valves to the plate with a single rivet. The first construction operates satisfactorily but is expensive both from the standpoint of parts and from manufacturing cost. The latter construction precludes independent selection of valve mounting pressures making it difficult to achieve a reliable seal with both valves.
One feature of the invention is the provision of a flapper valve assembly which includes an elongated fastener that extends through the mounting portion of the discharge leaf valve and the valve plate, securing the discharge leaf valve to the outer surface of the valve plate. The fastener has a portion projecting inwardly of the valve plate, through an aperture in the mounting portion of the suction leaf valve. The valve plate is secured to the body, as by a mounting bolt, with the mounting portion of the suction leaf valve held between the valve plate and the body. The parts are aligned by the elongated fastener and the mounting pressure may be independently selected.
Another feature is that the projecting portion of the elongated fastener extends into a hole on the body, adjacent the chamber, and thereby positions the valve plate and the suction valve with respect to the chamber. This facilitates the assembly of the parts in manufacture without barring additional elements which would add to the cost.
A further feature is that the fastener is a rivet having elongated body with an intermediate shoulder in engagement with the under surface of the valve plate and a head which secures the discharge leaf valve to the outer surface of the valve plate.